1. Field of the Invention
The present invention relates to controllers and patches for iontophoretic devices, and more particularly relates to ensuring compatibility of a reusable iontophoretic controller with an appropriate iontophoretic patch.
2. Description of the Prior Art
Iontophoresis can be defined as the introduction, by means of an electric current, of ions of soluble salts into the tissues of the body for therapeutic purposes. Iontophoretic devices have, in recent years, become an increasingly important means of administering therapeutic agents. Such systems offer advantages clearly not achievable by any other methods of drug administration requiring ingestion, or injection through the skin.
A recent development in iontophoretic devices is the use of a separate, reusable controller which is removably, electrically coupled to a patch containing the therapeutic agent or drug. The reusable controller includes a power source, such as a battery, and electronics which can control the amount of current applied to the patch as well as the amount of time current is to be applied. Such a device is described in U.S. Pat. No. 4,942,883. The iontophoretic device includes a power supply source and a microprocessor control system. The housing of the power supply source and microprocessor is arranged so that a carrier or patch containing a drug to be delivered to a patient can be attached to an open underside of the housing. The '883 patent teaches that the dosage rate (drug delivery time) and other required parameters for the known dosage to be administered by a certain patch are entered into the microprocessor control system by the user through the use of programmable pads or by a card or tape containing such information. A concern with this type of arrangement, a two component system having a reusable controller, is that the controller may be inadvertently used with an incompatible patch.
More specifically, if an error is made in programming the dosage rate or other dosage parameters, a patient may be severely harmed. For example, the patient may be burned by excessive current being applied to the patch or the patient may be harmed by an excessive amount of drug being driven into the patient's body. Alternatively, if not enough drug is being delivered to the patient, the patient's condition may worsen. The prior art provides no safety measures to ensure that a reusable controller is utilized with a compatible patch to provide proper drug dosages and time periods of dosages. Therefore, there is a need for a system of verifying that compatible controllers and patches are used when administering drugs transdermally with reusable controllers.
Yet another factor in the design of iontophoretic devices is to make the device cost efficient. In order for iontophoretic devices to be cost effective and competitive with conventional forms of therapy such as pills and subcutaneous injections, the cost of each component and feature must be kept to a minimum while ensuring the safety and health of the patient using the device. Accordingly, there is a need to keep the cost of the safety measures low while ensuring proper administration of a medicament.
It is therefore an object of the present invention to provide an iontophoretic device having a reusable controller which includes means to ensure that the patch and controller are compatible prior to any medicament being transdermally administered.
It is another object of the present invention to provide a cost efficient iontophoretic device having proper safety measures to ensure compatibility of the controller with the medicament containing patch.